Synthesis of poly(iminomethylene)s having para -substituted phenyl side groups

Misoo Kim, University of Rhode Island

Abstract

In this dissertation the synthesis of poly(iminomethylene)s having para-substituted phenyl side groups is presented. The poly(iminomethylene)s are unusual polymers in the sense that each atom of their main chain carries a side chain. The polymers have been reported to have a rigid helical configuration with four monomeric units per helical turn. The primary goal of this work was to develop a general and facile synthetic route for the formation of poly(iminomethylene)s and to establish whether these polymers have a rigid helical configuration or are mainly random coils.^ The monomeric para-substituted phenyl isocyanides were mainly obtained in good yields by using trichloromethyl chloroformate and triethylamine as the dehydrating agents. The poly(iminomethylene)s were prepared by adding the monomeric isocyanides to a stirred solution of NiCl$\sb2$ catalyst in methyl alcohol and stirring for one week at room temperature. The polymerization can be followed by observing the disappearance of the isocyanide using TLC as well as in the infrared absorption spectra of the reaction mixture. The precipitates that had formed were isolated by suction filtration and washed with methyl alcohol. The poly(iminomethylene)s were characterized by IR, UV-VIS, and NMR spectroscopy as well as gel permeation chromatography.^ The relationship between carbon chemical shifts and Hammett substituent constants for para-substituted phenyl isocyanides have been examined. Substituent chemical shifts at the isocyanide carbons, $\delta$ (C$\sb0$), and at the directly bonded carbons to the nitrogens of the isocyanides, $\delta$ (C$\sb1$), are correlated with the Hammett ($\sigma\sb{\rm R}\sp{\rm para}$) constants for the substituent of interest. Good linear plots were obtained by correlating $\sigma\sb{\rm R}\sp{\rm para}$ and $\Delta\delta$ (X-H) values at the C$\sb0$ position. ^

Subject Area

Chemistry, Organic|Chemistry, Polymer

Recommended Citation

Misoo Kim, "Synthesis of poly(iminomethylene)s having para -substituted phenyl side groups" (1996). Dissertations and Master's Theses (Campus Access). Paper AAI9707388.
http://digitalcommons.uri.edu/dissertations/AAI9707388

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